The work proposed is directed toward meeting the objectives of the Arizona SCOR, i.e., to elucidate the pathogeneses, pathophysiology, natural histories and factors contributing to the development of airway obstructive diseases (AOD) in order to prevent, detect, and/or treat AOD. To accomplish this, eight closely related projects, supported by Core units, comprise a multidisciplinary program involving and combining epidemiological, clinical, pathophysiological, experimental, and radiological approaches to the AOD problem. The prospective longitudinal epidemiological survey of the 4,000 members of l,650 Tucson households will continue to study the role of smoking, environmental, host, and genetic factors, including atopy, asthma, and history of bronchiolitis or other childhood respiratory illness, in contributing to the risk of developing chronic bronchitis, emphysema, or other chronic obstructive pulmonary disease (COPD), and provide further opportunity to evaluate methods for early detection of subclinical COPD. Air versus helium oxygen flow-volume curves and chest radiographs will be evaluated in this context. In subpopulations, there are specific studies of the role of air pollutants, aeroallergens, atopy and IgE levels, airway reactivity, or alpha -1- antitrypsin Pi MZ phenotype in the development of AOD. Pediatric lung function tests are being developed and will be utilized to study childhood airways disease and their long-term consequences. Experimental studies are being employed to relate structure to function in animals, in excised lung preparations, and human autopsy material, combining physiological measurements with simultaneous rotentgenographic image magnification and subsequent morphometry. Refinements of high resolution radiologic imaging will continue.